Question

I have a CLLocationCoordinate2D (c1) and a CLLocation (l1), so I have lat/long values for each point and I can calculate the distance in meters between them using:

[c1 distanceFromLocation:l1]

How can I find the coordinates of a point (c2) 100 meters closer to l1 than c1 (along the same bearing)?

I have calculated it using basic trig using the following:

1. used the difference in latitude and longitude to calculate the hypotenuse and angle
2. used the ratio between the distance to cl and the distance to c2 to get the hypotenuse of a triangle ending at c2
3. used cos and sin to calculate the longitude and latitude of c2

But this seems like a hacky way of doing it as it doesn’t take into account of curvature and seems to be using latitude and longitude in a way they are not supposed to be used. It does seem to work over short distances though.

Answer 1

Although Rickay’s answer was helpful, I eventually used the following excellent library which has many useful functions for Core Location calculations: https://github.com/100grams/CoreLocationUtils